Field
This document relates to a touch sensor integrated type display device which is capable of recognizing a user's touch.
Related Art
Recently, various input devices such as a keyboard, a mouse, a trackball, a joystick, and a digitizer have been used to configure an interface between users and home appliances or various kinds of information communication equipment. However, such input devices as a keyboard, a mouse, etc require the user to learn to use them and take up space. Therefore, the demand for input devices that are convenient, easy to use, and reduce erroneous operations is growing more and more. In response to this demand, a touch sensor for enabling a user to input information by directly touching the screen with their hand or a pen was suggested.
The touch sensor is simple to use, has less malfunctions, and enables the user to input without using an additional input device. In addition, the touch sensor can be applied to various display devices because it enables the user to operate it quickly and easily through content displayed on the screen.
Touch sensors can be classified into add-on type and on-cell type. In the add-on type, a display device and a touch panel having a touch sensor are separately manufactured, and the touch panel is attached onto an upper substrate of the display device. In the on-cell type, a touch sensor is directly formed on the surface of an upper glass substrate of a display device.
However, the add-on type sensor has a structure in which the completed touch panel is mounted on the display device and has various problems, such as increased thickness or reduced visibility due to low brightness of the display device.
In addition, the on-cell type touch sensor has a structure in which a touch panel is formed on the upper surface of the display device and can have a reduced thickness compared to the add-on type but still has the problem of the increase in entire thickness due to a driving electrode layer, a sensing electrode layer, and an insulation layer for insulating the driving electrode layer and the sensing electrode layer, which constitute the touch sensor. As such, the number of processes and the manufacturing cost in the on-cell type touch sensor is increased.
One solution to the problem described hereinabove can be found in U.S. Pat. No. 7,859,521, titled “touch sensor integrated type display device.”
The touch sensor integrated type display device disclosed in U.S. Pat. No. 7,859,521 measures the amount of change in electrostatic capacitance caused by a touch and recognizes the presence or absence of a touch and a touch position by dividing common electrodes for display to use them as touch driving electrodes and touch sensing electrodes.
With the configuration of U.S. Pat. No. 7,859,521, electrodes performing the same function are connected to each other by wires in a non-contact manner because the touch driving electrodes and the touch sensing electrodes are formed on the same layer. That is, the touch driving electrodes are connected to touch driving electrode connecting wires via driving electrode contact holes, and the touch sensing electrodes are connected to each other by touch sensing electrode connecting wires via sensing electrode contact holes. Hence, the touch driving electrodes and the touch sensing electrodes are not in electrical contact with each other.
However, the touch sensor integrated type display device disclosed in U.S. Pat. No. 7,859,521 has a complicated structure where both the touch driving electrodes and the touch sensing electrodes are formed on a single layer of common electrodes for display and have separate wires for connecting the divided driving electrodes and contact holes for connecting these wires.
As such, the conventional touch sensor integrated type display device has the problems of complex design and degradation of display characteristics because of different types of display pixels arranged within a unit touch electrode in a complicated manner.